/**
    * Copyright 2005-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.opensource.org/licenses/ecl2.php
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.kuali.rice.krad;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.config.property.ConfigContext;
  import org.kuali.rice.core.api.exception.RiceRuntimeException;
  import org.kuali.rice.kim.api.identity.Person;
  import org.kuali.rice.kim.api.services.KimApiServiceLocator;
  import org.kuali.rice.krad.util.SessionTicket;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * Holds info about the User Session
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class UserSession implements Serializable {
      private static final long serialVersionUID = 4532616762540067557L;
  
      private Person person;
      private Person backdoorUser;
      private AtomicInteger nextObjectKey;
      private Map<String, Object> objectMap;
      private String kualiSessionId;
  
      /**
       * Returns the session id. The session id is a unique identifier for the session.
       * @return the kualiSessionId
       */
      public String getKualiSessionId() {
          return this.kualiSessionId;
      }
  
      /**
       * Sets the session id.
       * @param kualiSessionId the kualiSessionId to set
       */
      public void setKualiSessionId(String kualiSessionId) {
          this.kualiSessionId = kualiSessionId;
      }
  
      /**
       * Creates a user session for the principal specified in the parameter.
       * Take in a netid, and construct the user from that.
       *
       * @param principalName
       */
      public UserSession(String principalName) {
          initPerson(principalName);
          this.nextObjectKey = new AtomicInteger(0);
          this.objectMap = Collections.synchronizedMap(new HashMap<String,Object>());
      }
  
      /**
       * Loads the Person object from KIM. Factored out for testability.
       * @param principalName the principalName
       */
      protected void initPerson(String principalName) {
          this.person = KimApiServiceLocator.getPersonService().getPersonByPrincipalName(principalName);
          if (this.person == null) {
              throw new IllegalArgumentException(
                      "Failed to locate a principal with principal name '" + principalName + "'");
          }
      }
  
      /**
       * Returns the id of the current user.
       * @return the principalId of the current user in the system, backdoor principalId if backdoor is set
       */
      public String getPrincipalId() {
          if (backdoorUser != null) {
              return backdoorUser.getPrincipalId();
          }
          return person.getPrincipalId();
      }
  
      /**
       * Returns the name of the current user.
      * @return the principalName of the current user in the system, backdoor principalName if backdoor is set
      */
     public String getPrincipalName() {
         if (backdoorUser != null) {
             return backdoorUser.getPrincipalName();
         }
         return person.getPrincipalName();
     }
 
     /**
      * Returns who is logged in. If the backdoor is in use, this will return the network id of the person that is
      * standing in as the backdoor user.
      *
      * @return String
      */
     public String getLoggedInUserPrincipalName() {
         if (person != null) {
             return person.getPrincipalName();
         }
         return "";
     }
 
     /**
      * Returns a Person object for the current user.
      * @return the KualiUser which is the current user in the system, backdoor if backdoor is set
      */
     public Person getPerson() {
         if (backdoorUser != null) {
             return backdoorUser;
         }
         return person;
     }
 
     /**
      * Returns the actual current user even if the backdoor is in use.
      * @return the KualiUser which is the current user in the system
      */
     public Person getActualPerson() {
         return person;
     }
 
     /**
      * override the current user in the system by setting the backdoor networkId, which is useful when dealing with
      * routing or other reasons why you would need to assume an identity in the system
      *
      * @param principalName
      */
     public void setBackdoorUser(String principalName) {
         // only allow backdoor in non-production environments
         if (!isProductionEnvironment()) {
             this.backdoorUser = KimApiServiceLocator.getPersonService().getPersonByPrincipalName(principalName);
         }
     }
 
     private boolean isProductionEnvironment() {
         return ConfigContext.getCurrentContextConfig().isProductionEnvironment();
     }
 
     /**
      * clear the backdoor user
      */
     public void clearBackdoorUser() {
         this.backdoorUser = null;
     }
 
     /**
      * allows adding an arbitrary object to the session and returns a string key that can be used to later access this
      * object from
      * the session using the retrieveObject method in this class. This allows for a prefix to be placed in front of the
      * incremented key. So if the prefix is "searchResults" and the nextObjectKey (local int that holds the key value)
      * is 2 then
      * the new key will be "searchResults3". "searchResults3" will be returned from the method.
      *
      * @param object
      */
     public String addObjectWithGeneratedKey(Serializable object, String keyPrefix) {
         String objectKey = keyPrefix + nextObjectKey.incrementAndGet();
         objectMap.put(objectKey, object);
         return objectKey;
     }
 
     /**
      * allows adding an arbitrary object to the session and returns a string key that can be used to later access this
      * object from
      * the session using the retrieveObject method in this class. The key is generated from an integer and incremented
      * for every
      * object added.  So the first object added with have a key of "1".  This key will be returned from the method.
      *
      * @param object
      */
     public String addObjectWithGeneratedKey(Object object) {
         String objectKey = nextObjectKey.incrementAndGet() + "";
         objectMap.put(objectKey, object);
         return objectKey;
     }
 
     /**
      * allows adding an arbitrary object to the session with static a string key that can be used to later access this
      * object from
      * the session using the retrieveObject method in this class
      *
      * @param object
      */
     public void addObject(String key, Object object) {
         objectMap.put(key, object);
     }
 
     /**
      * allows for fetching an object that has been put into the userSession based on the key that would have been
      * returned when
      * adding the object
      *
      * @param objectKey
      */
     public Object retrieveObject(String objectKey) {
         return this.objectMap.get(objectKey);
     }
 
     /**
      * allows for removal of an object from session that has been put into the userSession based on the key that would
      * have been
      * assigned
      *
      * @param objectKey
      */
     public void removeObject(String objectKey) {
         this.objectMap.remove(objectKey);
     }
 
     /**
      * allows for removal of an object from session that has been put into the userSession based on a key that starts
      * with the given
      * prefix
      */
     public void removeObjectsByPrefix(String objectKeyPrefix) {
         synchronized (objectMap) {
             List<String> removeKeys = new ArrayList<String>();
             for (String key : objectMap.keySet()) {
                 if (key.startsWith(objectKeyPrefix)) {
                     removeKeys.add(key);
                 }
             }
 
             for (String key : removeKeys) {
                 this.objectMap.remove(key);
             }
         }
     }
 
     /**
      * @return boolean indicating if the backdoor is in use
      */
     public boolean isBackdoorInUse() {
         return backdoorUser != null;
     }
 
     /**
      * Adds the given SessionTicket to the objectMap and returns the associated key
      *
      * @param ticket - SessionTicket to add
      * @return the objectMap key for the ticket as a String
      */
     public String putSessionTicket(SessionTicket ticket) {
         return addObjectWithGeneratedKey(ticket);
     }
 
     /**
      * Retrieves all SessionTicket instances currently in the UserSession#objectMap
      *
      * @return List<SessionTicket> contained in user session
      */
     public List<SessionTicket> getAllSessionTickets() {
         List<SessionTicket> sessionTickets = new ArrayList<SessionTicket>();
 
         synchronized (objectMap) {
             for (Object object : objectMap.values()) {
                 if (object instanceof SessionTicket) {
                     sessionTickets.add((SessionTicket) object);
                 }
             }
         }
 
         return sessionTickets;
     }
 
     /**
      * Retrieves all SessionTicket instances currently in the UserSession#objectMap that are of a given ticket type
      *
      * @return List<SessionTicket> contained in user session
      */
     public List<SessionTicket> getAllSessionTicketsByType(String ticketTypeName) {
         List<SessionTicket> sessionTickets = new ArrayList<SessionTicket>();
 
         for (SessionTicket ticket : getAllSessionTickets()) {
             if (StringUtils.equalsIgnoreCase(ticket.getTicketTypeName(), ticketTypeName)) {
                 sessionTickets.add(ticket);
             }
         }
 
         return sessionTickets;
     }
 
     /**
      * Determines if the UserSession contains a ticket of the given type that matches the given context. To match context
      * the ticket must
      * contain all the same keys at the given context and the values must be equal with the exception of case
      *
      * @param ticketTypeName - Name of the ticket type to match
      * @param matchContext - Map on context parameters to match on
      * @return true if a ticket was found in the UserSession that matches the request, false if one was not found
      */
     public boolean hasMatchingSessionTicket(String ticketTypeName, Map<String, String> matchContext) {
         boolean hasTicket = false;
 
         for (SessionTicket ticket : getAllSessionTicketsByType(ticketTypeName)) {
             Map<String, String> ticketContext = ticket.getTicketContext();
 
             boolean keySetMatch = ticketContext.keySet().equals(matchContext.keySet());
             if (keySetMatch) {
                 boolean valuesMatch = true;
                 for (String contextKey : ticketContext.keySet()) {
                     String ticketValue = ticketContext.get(contextKey);
                     String matchValue = matchContext.get(contextKey);
                     if (!StringUtils.equalsIgnoreCase(ticketValue, matchValue)) {
                         valuesMatch = false;
                     }
                 }
 
                 if (valuesMatch) {
                     hasTicket = true;
                     break;
                 }
             }
         }
 
         return hasTicket;
     }
 
     /**
      * retrieves an unmodifiable view of the objectMap.
      */
     public Map<String, Object> getObjectMap() {
         return Collections.unmodifiableMap(this.objectMap);
     }
 
     /**
      * clear the objectMap
      */
     public void clearObjectMap() {
         this.objectMap = Collections.synchronizedMap(new HashMap<String,Object>());
     }
 }